Hi all,
some (longterm stable) kernel got patches who seem to make them incompatible
with cryptsetup. See for details:
http://thread.gmane.org/gmane.linux.kernel.stable/165742
I tried the git version of cryptsetup and that seem to fix it at least for
4.1.18. I noticed no problems so far.
A new tarball release would be a good idea I think.